[dm-devel] [PATCH v7 0/6] block: Introduce REQ_ALLOCATE flag for REQ_OP_WRITE_ZEROES

[Martin K. Petersen]

Christoph,

> I am very much against that for the following reason:
>
>  - the current REQ_OP_DISCARD is purely a hint, and implementations can
>    (and do) choose to ignore it
>
>  - REQ_OP_WRITE_ZEROES is an actual data integrity operation with
>    everything that entails

If you want to keep emphasis on the "integrity operation" instead of the
provisioning aspect, would you expect REQ_ALLOCATE (which may or may not
zero blocks) to be considered a deterministic operation or a
non-deterministic one? Should this depend on whether the device
guarantees zeroing when provisioning blocks or not?

-- 
Martin K. Petersen	Oracle Linux Engineering